What The Heck Is A Red Flag Warning? Here's What To Know (And What To Do)

Californians are witnessing more and more red flag warnings as fire season gets longer and more intense. But what is a red flag warning, and how much precaution should you take if you live in an area under one?

A red flag warning means that if a fire sparks, conditions are just right for that blaze to burn fast and quick. They're posted online by the National Weather Service, and agencies like Cal Fire use them to know how to staff units.

The warnings are announced when sustained winds average 15 mph or greater, the temperature is 75 degrees or warmer, dry lightning strikes take place, and when the level of humidity is less than or equal to 25 percent, said Sacramento based Warning Coordination Meteorologist Michelle Mead.

"It basically means the weather conditions are ripe to the point that if a fire should start it could very easily get out of hand; the drier the air the faster the fire can spread,” Mead said.

Before a red flag warning goes out, NWS releases a fire weather forecast about a week prior with a headline saying something like “gusty winds and low humidity five days out.” At about three days before the warning a Fire Weather Watch is sent out, so the fire community can prep resources.

“Then the warning means the conditions are happening or imminent and they are ready to go,” Mead said.

Before the internet these virtual red flag warnings were actual pieces of cloth or signs used from 1950s through the '70s.

“The red flag program historically started in California, and at one time Cal Fire units actually flew a red flag on a flagpole at the ranger’s office . . . that was some indication of severe fire weather and dry fuels,” said Brenda Belongie, lead meteorologist of the U.S. Forest Service's Predictive Services in Northern California.

But there are still areas that hoist a red flag in the air when fire danger is high, said Larry VanBussum, NWS Operations Coordinator for the National Weather Service in Boise, Idaho.

“There’s still a place in eastern Oregon that when we issue a red flag warning they’ll put up a red flag outside their district office, and businesses put up red flags to let folks know,” VanBussum said.

And the red flag warnings we hear on the radio or on TV now are a big deal. Mead, with NWS, said these warnings are just as important as alerts for other natural disasters like hurricanes or earthquakes. It’s also important since California is seeing blazes and the effects of fire all year round.

“Last year was a perfect example,” Mead said. “We had fires in December all the way to the end of the year and then we had the mudslides and debris flow shortly after.”

In 2017, Cal Fire's Scott McClean said 46 people died in California wildfires. He said this year six fire personnel have been killed in fires.

No matter if people live in rural areas or cities, McClean said everyone should take red flag warnings seriously.

"These fires are not giving anybody any time. Time is the enemy,” said McClean. “You need to be prepared so all you do is grab and run and get in the car and get out."

During a red flag warning he said everyone should stop activities that create sparks, such as mowing lawns and to double check things like chains on trailers. The Carr Fire that destroyed more than 1,000 homes in the Redding area earlier this year started when a tire on a travel trailer blew out, causing the rim to spark when it rolled along the pavement.

“It's very critical,” McClean said. “It’s not a joke, it’s not a game and we’ve seen the ramifications of it this year. We’ve already burned 1.35 million acres in this state between Cal Fire and the Forest Service’s jurisdiction.”

In case evacuations are necessary he said people need to have a planned escape route, and to have a go-bag ready with enough food, water, and clothes for three days. He said to leave enough room in the bag for items such as hard drives, cash, prescriptions and any non-replaceable keepsakes like photos.